Plant materials
Six-months-old P. massoniana seedlings with similar size were
selected and transplanted into the flowerpots filled with approximate 10
kg the aforementioned substrate soil containing different Ca levels. The
transplanted seedlings were cultivated in a greenhouse with normal
watering condition. Other cultivation conditions as follows: light/dark
regime 15/9 h, temperature 21/27°C (night/day), relative humidity
60-70% and photosynthetically active radiation 210 μmol
m-2 s-1. After two months growth,
the fresh leaf tissues were collected for the subsequent experimental
analysis. Three biological replicates were performed for each treatment
group.